Drafting instrument



Feb. 14, 1939.

F. DOETZEL, JR DRMTING INSTRUMENT Filed Feb 23, 1937 2 Sheets-Sheet 1 ADCDtFG INVENTOR. FRED pofrza /k Feb; 14, 1939.

F. DOETZEL. JR 2,147,017 DRAFTING INSTRUMENT Filed Feb. 23, 1937 2 Sheets-Sheet 2 INVENTOR. FRED DOE 7'ZEL,JA?

Patented Feb. 14, 1939 UNITED STATES PATENT OFFICE 2,147,017 DRAFTING INSTRUMENT Fred Doetzel, Jr., Cedar Rapids, Iowa Application February 23, 1937, Serial No. 127,063

3 Claims.

This invention'relatesto instruments and has particular relation to, a draftsmans instrument.

In making mechanical drawings, the drafting of a plurality of parallel lines, as in cross-hatching, surface shading, parallel lines for lettering and the like, is a tedious and painstaking task under ordinary conditions as extreme accuracy is required in the use of the pencil or pen and straight edge so that the lines are evenly spaced.

l0 I have, however, devised an attachment, a mod i-fication of the usual triangle 'which'may be used not only in its ordinary use as a triangle but also as a step-by-step guide for making parallel lines of any selected spacing.

An object of my invention is to provide an instrument which affords a quickly adjustable guide for making parallel lines of any desired spacing.

Another object and feature of my invention is to provide a device of the above character in which the portions of the device which are cut away for finger holds may be utilized for links to cause the parts of the device to move in parallel relation.

Another object of my invention is to provide an extremely simple and reliable structure of the above character.

Other and further features and objects of the "invention will be more apparent to those skilled in the art upon a consideration of the accompanying. drawings and following specifications,

wherein is disclosed several exemplary embodiments of the invention, with the understanding,

' however, that such changes maybe made therein as fall within the scope of the appended claims,

- without-'Ideparting.from the spirit of the invention.

In said drawings:

Figure l is a plan view illustrating a draftsmans instrument embodying a preferred form of my invention.

Figure 2 illustrates how the parallel lines drawn with the instrument may be used as a guide for lettering.

Figure 3 illustrates how parallel lines may be drawn with this instrument.

Figure 4 is a plan view of a draftsmans instrument constructed according to another embodiment of my invention, and

Figure 5 is a plan view of still another embodi- 50, ment of my invention.

In the device illustrated in Fig. 1 a pair of right angle triangles l0 and II are employed in backto-back reversed position so as to form a parallelepiped.

I may employ a punch or sharp knife to cut away finger holds l2 and I3 from the respective triangles. Theportions cut away are preferably in the form of bifurcated members such as illustrated at l4 and I6 for the provision of pivots but obviously these links may be of any other 5 suitable shape. The links [4 and I6 are pivotally engaged at the adjacent sides of the two triangles by means of pivots such as the hollow rivets I! here illustrated. I also preferably secure a small circular stop l8 at a point substantially l0 midway at the edge of one of the triangles and provide a long tapered arm l9 which is pivotally engaged to the edge of the other triangle adjacent the pin or stop I8. The arm I9 is preferably secured to the triangle by means of a l 5 knurled nut 2i which is threadedly engaged on the bolt 22 which passes through the triangle II], the head of the bolt-22 being counter-sunk in the lower face of the triangle l0.

In us-ing the instrument illustrated in Figure 1, 20 the thumbnut 2| is loosened andthe arm l9 rotated until the pin l8 strikes the arm when the triangle ll is moved downwardly. The position of the arm I9 is then so determined as to limit the movement of the triangle H with respect to the triangle. Ill to a degree depending on the width of the spacing of the lines to be made by the instrument. In using the instrument the fingers of the right hand are inserted in the opening l2 to hold the triangle I 0 against the face go of the drawing board. The fingers of the left hand are inserted in the opening l3 and the triangle H is moved downwardly until the pin l8 strikes the arm IS. The triangle II is then held solidly-against the face .of the drafting board and the triangle II! is moved downwardly until it strikes the triangle II. A line may be ruled along the upper edge of the triangle l0 and the shifting process of the triangle is repeated and another line is ruled along the upper edge of the 4 triangle It]. This process may be repeated as long as it is necessary to make lines and obviously the triangles may be moved down or across the board as desired. The easiest manipulation of the instrument is secured by moving it down- 45 wardly across the board or from left to right. Of course it can be moved in a reversed direction and the lower triangle used for ruling.

If it is desirable to make guide lines for lettering as in Figure 2 the triangles may be placed .50 on the board in the position as shown in Figure 1. If it is necessary to make oblique lines as illustrated in Figure 3 the triangles may be turned accordingly. It may be noticed that the links M and 16 are substantially parallel to the upper edge of triangle l0 and the movement of the triangles will be substantially perpendicular to theupper edge of triangle II]. In Figure 1 the full line of the triangles illustrate the beginning and end position of the triangles while the dotted lines indicated at 23 illustrate the intermediate position of triangle while the triangles are being moved into a new position after one line has been completed.

In Figure 4.1 have illustrated another embodiment of my invention in which two IS-degree triangles are employed. The larger triangle 4| is of the usual construction except that the central portion is cut away as indicated at 42 in the form of a 45-degree triangle, the edges of which are parallel to triangle 4|. The triangular piece of material 43, cut out of triangle 4|, is cut away at one edge thereof as indicated at 44 so that it may be received within the opening 42 in triangle 4| and may move freely within this opening. 7 r

Two finger holds 46 and 41 are preferably cut in triangles 4| and 43 respectively and these cutaway portions are used to form links 48 and 49.

The links 48 and 49 are pivotally engaged, in parallel relation, to triangles 4| and 43 by means of hollow pivots 5|. In the present instance the links 48 and 49 are located substantially parallel to the right hand or vertical edge of the triangle 4| and in use the triangles are preferably moved from left to right. Ruling may be done on the edge 52 or the edge 53. The dotted line 55 illustrates the intermediate position of the center triangle while they are being moved from one position to another.

In using the triangles for ruling, a line may be drawn on the edge 52 or 53, the triangle 43 moved to a new position, the triangle 4| moved to abut against the triangle 43 and another parallel line ruled-on the edges 52 or 53. The movement of triangles 4| and 43 may be limited, as described before, by means of the pin or stop 54 on one triangle and a lever 56 pivotally engaged to the other triangle by means of the knurled nut 51 and bolt 58. l

' In another embodiment of the device illustrated in Figure 5 I preferably employ a 45-degree triangle 6| having the lower end thereof cut away as indicated at 62. Links 63 and 64 are pivotally connected to the members 6| and 62 on the triangle as before described in connection with the first described embodiments of the invention. A stop 66 is provided on one portion of the triangle 6| and an arm 61 is pivotallyenuntil it strikes the lower portion 62.

gaged to the other portion of the triangle by means of a knurled nut 68 and bolt 10. The links 63 and 64 are provided from material left from cutting the finger holds 69 and 1|.

When the device shown in this embodiment of my invention is used in ruling lines the edge 12 is used as a guide for drawing the lines. After ruling a line along the edge 12, the lower portion 62 is moved downwardly to the dotted position shown. The movement thereof is limited by the arm 61 and the stop 66 and the upper portion of the triangle is then moved downwardly Another line may then be ruled on the edge 12.

It is apparent that the devices constructed according to my invention are extremely simple in construction and operation and. that there is very little waste in making the device.

Modifications of my invention may be made by those skilled in the art and such modifications may be made without departing from the spirit and scope of my invention as set forth in the appended claims.

I claim as my invention:

1. A'method of forming a drafting instrument for ruling a series of equally spaced parallel lines comprising providing a member in the form of a parallelepiped, cutting the member across one diagonal, cutting finger holds in the two triangular portions, using the cut-out finger hold portions as links, and connecting the two triangular portions by pivotally engaging the links thereto on parallel axes.

2. A method of forming a drafting instrument for ruling of a series of parallel lines comprising providing a guide member, cutting the guide member in two portions, cutting finger holds in the said two portions, forming links from these cut-out finger hold members, and engaging the two portions of the guide members for swinging movement with respect to each other by means of pivotally engaging the links to the aforementioned portions.

3. In a drafting instrument, two right-angled triangular members formed by cutting a parallelogram along a diagonal thereof, the angles of the parallelogram being so chosen that the said diagonal and an adjacent side of each triangular member are at right angles with respect to one another to thereby form a pair of identical rightangled triangles, and parallel links pivotally engaging the triangles to each other to permit pivotal parallel movement of one with respect to the other.

FRED DOETZEL, JR. 

